Performance of Pd-impregnated Sr1.9FeNb0.9Mo0.1O6-δ double perovskites as symmetrical electrodes for direct hydrocarbon solid oxide fuel cells

Symmetrical solid oxide fuel cell (SSOFC) is one of efficient ways to simplify preparation process, reduce manufacturing cost, and improve redox stability and reliability. Here, we report the performance of Sr-deficient Sr1.9FeNb0.9Mo0.1O6-delta (SFNM) double perovskites as symmetrical electrodes for direct-hydrocarbon solid oxide fuel cells and significant improvement of electrochemical performance. The SFNM exhibits good structural stability, suitable thermal expansion coefficient and highly chemical compatibility with Sm0.2Ce0.8O1.9 (SDC) and La0.9Sr0.2Ga0.8Mg0.2O3-delta (LSGM) electrolytes in both air and 5% H-2/Ar atmospheres. The area specific resistance of SFNM electrode is decreased by 3.6 and 8.4 times at 800 degrees C in air and H-2, respectively, as compared to the pristine Sr2FeNbO6-delta-electrode. The electrochemical performance is further improved by introducing a small amount of Pd to form Pd-impregnated SFNM composite electrode (Pd-SFNM). The SSOFCs with Pd-SFNM after two-time impregnation treatments as the electrodes achieve impressive electrochemical performances in different fuels. The Pd-SFNM symmetrical electrode reveals good electrochemical stability operating on CH4-CO2 mixed gas. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.